New WebKit privacy restrictions: impact on data tracking

On October 19, 2026, Apple’s WebKit team announced new privacy restrictions. It aims to prevent cross-site tracking through identity resolution infrastructure. 

In this post, we’ll explain what restrictions Apple is introducing, how they may impact data tracking, whether server-side tracking setups are affected, and practical steps to take.

Apple’s protection targets identity resolution. It involves third-party services that collect personally identifiable information (PII), such as an email address, and link it to a specific identifier that is later used to recognize the same users across websites and devices.

This identifier then helps build a profile of the user and target them with relevant ads on multiple platforms.

The restrictions are going to interrupt this process before the personal information reaches the third-party infrastructure. 

According to WebKit, the protection is included in the following operating system releases:

• iOS 27
• iPadOS 27
• macOS 27
• visionOS 27

The restriction is applied at the domain level. It means that changing the structure of a request alone won’t bypass the protection.

Apple’s announcement does not provide a list of the domains affected by the restriction. It only describes the type of infrastructure that is targeted.

The main consequence is that some requests made by a website may never reach the destination.

Although it is too early to determine the impact of these restrictions, some of our clients have already noticed underreporting in services related to call tracking on their websites. While these discrepancies may be related to Apple’s new restrictions, it is still too early to draw any definitive conclusions about their potential impact on tracking requests.

Apple’s restriction targets identity resolution infrastructure from Safari and WebKit, not server-to-server communication.

Here’s what Apple’s WebKit team states:

Therefore, this release should not affect tracking setups that use server-side tracking.

✅ Check the share of Apple users in your audience (such data is usually available in tools like GA4) to understand how your tracking setup may be affected by these restrictions.

✅ Monitor your data for unexpected drops in reported traffic, conversions, or other key metrics.

✅ Consider switching to server-side tracking for the platforms where possible to reduce the setup's reliance on client-side tracking (in-browser only). We have a list of tags for platforms that support server-side tracking for further reference.